The co-operative is sticking to its conservative forecast of a 13 million tonne harvest despite the record-breaking start.

Mr Daw said CBH had plans for emergency storage in the Esperance zone and was boosting its shipping capacity in preparation for an unprecedented harvest.

"I'm confident with the 2.5mt forecast, which is 400,000t more than we have ever had but in saying that it could exceed it by quite a bit. I wouldn't like to say by how much because it worries me at night," he said. "Barley and wheat yields are still exceptional with many growers averaging around 4t/ha."

Mr Hallam said the bumper crop had followed three disastrous seasons.

"For us to come off the three worst years on record and to have one like this is definitely going to dig us out of the overdraft but we could do with stringing a few together," he said.

"Spare a thought for guys out around Southern Cross who have had a run of terrible years and are still doing it tough."

Mr Hallam's 69-year-old father John played a key role in organising donations of hay and old-season grain from the Grass Patch district to farmers on the edge of the eastern Wheatbelt where crops failed.

CBH marketing and trading manager Jason Craig said growers delayed selling wheat last week as prices were under $300/t.